This invention relates to a device for towing vehicles and, in particular, to a carriage or trailer for towing the vehicles by engaging and lifting a set of wheels of the vehicle. The invention also concerns a multi-function carriage that can be converted easily into a utility trailer or similar device.
Many conventional towing devices lift and pull a vehicle by hooking a chain or a sling to the vehicle bumper, axle or undercarriage. Devices of this nature are generally restricted to use by wrecker services for towing disabled vehicles. Another typical towing device consists primarily of a tow bar mounted between a trailer hitch, attached to the towing vehicle, and a mounting bracket, attached to the towed vehicle. Devices of this nature are frequently used to tow operable vehicles, for instance, when an automobile is towed behind a recreational vehicle or truck. In this instance, the towed vehicle is pulled behind the towing vehicle with all four wheels in contact with the ground. However, certain automobile manufacturers refuse to warrant the vehicles towed in this manner.
An alternative type of device raises the car by supporting the front or rear wheels of the automobile off the ground. This alternative device includes its own set of ground engaging wheels for providing the necessary support to the towed vehicle. One disadvantage of these devices is that they provide inadequate lateral stability for side-to-side motion of the towed vehicle, particularly when negotiating a turn. Some of these devices, such as that described in the patent to Porter, Sr., et al., U.S. Pat. No. 4,573,857, use straps engaged about the wheels to hold the wheels in place. These wheel straps are typically cumbersome and difficult for many people, such as the handicapped or elderly, to attach. Further, there is a tendency for the straps to work loose when the towed vehicle is pulled around a corner because the vehicle wheels have a tendency to shift longitudinally and laterally as the turn is made.
Another difficulty with many of the prior art devices is that they involve fairly complicated and heavy frame structures so that it is difficulty to maneuver the towed vehicle onto the device. In addition, many of these devices have the towing device wheels outboard of the towed vehicle wheels, so that the towing device is relatively wide and difficult for the driver of the towing vehicle to keep on the road. Another problem of the prior art towing devices is that complicated mechanisms are provided for steering of the towing device when the towing vehicle negotiates a turn.
In view of the difficulties and limitations of the prior art towing devices, it is desirable to provide a towing device that is lightweight, easy to control while driving, and easy to maneuver a towed vehicle thereon. It is also important that the device provide adequate lateral stability of the towed vehicle to prevent excessive sway or yaw when negotiating a turn, yet permit longitudinal and lateral shifting of the vehicle wheels. It is also desirable that the device be lightweight, multi-functional and easy to manipulate and store.